The widespread acceptance and use of hand-held, portable cellular telephones has been accompanied by increasing concern regarding possible harmful effects of radiation emitted by such devices. Hand-held cellular telephones typically have an elongated housing with a speaker located near the top of the housing and an antenna extending upward vertically from the housing. In use of this type of telephone, the user's head comes into close proximity to the antenna when his or her head is placed with an ear adjacent to the speaker. Thus, when the device is transmitting, a substantial amount of electromagnetic energy is projected directly onto the user's head at close range.
Cellular telephones generally operate in the microwave portion of the electromagnetic spectrum at a frequency of 800 to 900 megahertz. At the usual short distance between the user's head and the antenna, a substantial radiation field is generated at this microwave frequency. While the extent of biological damage that might result from exposure to such a radiation field has not been established, some indications of severely detrimental results have been publicized recently. Provision of a means for reducing the level of radiation to which a user is subjected would therefore be clearly desirable, particularly if this could be accomplished without adversely affecting the operation of the telephone.